#include "stdstuff.h"

#include "Parser.h"


int main () {

  String2002 str;
  ExpTreeNode *root;

  for (;;) {

    cout << "\nEnter an expression (STOP to terminate).\n: ";
    cin >> str;

    // convert to upper case
    for (int i = 0; i < str.length(); i++) {
      str[i] = (char) toupper(str[i]);
    }

    if (str == "STOP") {
      pause();
      return 0;
    }

    cout << endl; // space the output

    if ((root = createExpTree ((String2002) str)) == NULL) {
      cout << "That is not a valid expression.\n";
    } else {
      cout << "The expression is valid.  Its value is "
           << evaluateExpTree(root) << ".\n";
      cout << "Infix form ";
      outputInfixExpression (root);
      cout << endl;
      cout << "Postfix form ";
      outputPostfixExpression (root);
      cout << endl;
      deleteExpTree (root);

    }

  }

}